Nowadays, digital image processing devices such as digital cameras, image scanners, image printers and the like are widely used for processing and outputting images. Ideally, the output images of the digital image processing devices are substantially identical to the real images. For example, it is important to discriminate whether the printed image outputted from the image printer is very close to the electronic image or whether the electronic image generated by the image scanner is very close to the manuscript image. That is, an image analysis method is needed to determine the difference between the output image and the real image. Generally, human visual recognition is a simple image analysis technique to directly determine the difference between the output image and the original image with the naked eyes. As known, the human visual recognition is both laboring and time-consuming. In addition, the human visual recognition is a very subjective judgment of the image difference. For efficiently analyzing large amounts of data, many image analysis techniques have been provided for the extraction of quantitative data from images. In this context, an image analysis program used for image analysis is illustrated.
Generally, the image to be analyzed is divided into a plurality of image blocks. According to the attributes of the individual image blocks, these image blocks are classified as picture blocks, text blocks and the like. For a designated image analysis program, the image with a specified image block arrangement mode may be analyzed. That is, this designated image analysis program fails to analyze the images with different image block arrangement modes. Please refer to FIG. 1, which is a schematic views illustrating three images with different image block arrangement modes. In FIG. 1, a first image IA, a second image IB and a third image IC are shown. The first image IA includes five image blocks 1, 2, 3, 4 and 5. The second image IB is obtained by rotating the first image IA through 90 degree. The third image IC includes the five image blocks 1, 2, 3, 4 and 5 with different location arrangement from the first image IA.
FIG. 2(a) is a schematic block diagram illustrating a concept of analyzing images by a conventional image analysis technique. As shown in FIG. 2(a), the first image analysis program PA is specialized in analyzing the first image IA, the second image analysis program PB is specialized in analyzing the second image IB and the third image analysis program PC is specialized in analyzing the third image IC. Please refer to FIGS. 1 and 2. For analyzing these images IA, IB and IC, the programmers should have previously written the position data about the five image blocks of the images IA, IB and IC into the image analysis programs PA, PB and PC, respectively. Accordingly, the image analysis programs PA, PB and PC may be used to analyze the images IA, IB and IC, respectively.
Although the second image IB is simply obtained from rotation of the first image IA, the first image analysis program PA may only analyze the first image IA rather than the second image IB if the influence of image rotation is not attached to the first image analysis program PA. For analyzing the second image IB, the second image analysis program PB specialized in analyzing the second image IB is indispensable or otherwise the first image analysis program PA is modified to take the image rotation into consideration. As known, modifying the first image analysis program PA is more difficult and time-consuming than writing the second image analysis program PB.
In a case that an image rotation command RC is added to the first image analysis program PA during the programmer edits the program, the first image analysis program PA may analyze the first image IA as well as rotated first image IA (i.e. the second image IB). The related concept of analyzing images is illustrated with reference to a schematic block diagram of FIG. 2(b). The first image analysis program PA including the image rotation command RC, however, still fails to analyze the rearranged image blocks 1˜5 of the third image. On the other hand, a third image analysis program PC specialized in analyzing the third image IC should be additional written according to the rearranged image blocks 1˜5 of the third image.
As previously described, the images with different image block arrangement modes are considered as different images by the image analysis programs. As a result, the images with different image block arrangement modes fail to be analyzed by a common image analysis program. Even if the image rotation command RC is added to the first image analysis program PA, only the first image IA and the second image IB can be analyzed. Under this circumstance, the third image IC or more images with different image block arrangement modes fail to be analyzed by the first image analysis program PA including the image rotation command RC.
By means of the conventional image analysis technique described above, many image analysis programs should be edited to analyze corresponding block arrangement modes of images. Such an image analysis technique is troublesome and inefficient. Therefore, there is a need of providing an image analysis method by using a single image analysis program to analyze images with different image block arrangement modes.